The present invention relates to a tape loading device for a tape recorder including a rotary magnetic head drum such as a video tape recorder or a digital audio tape recorder.
As is well known, conventional video tape recorders are classified into a "U" loading type one and an "M" loading type according to the shape of the travelling path of tape. The "U" loading type recorders are classified again into an old one and a new one.
The travelling load actuated on the tape is largest in the case of the "M" loading type recorder. The next one is the new "U" loading type recorder. The old "U" loading type recorder is subjected to a smaller load and therby known as the most stable and preferable one when the travel of tape is considered.
Although the old "U" loading type recorder has advantages of the stability of the travelling system and of the simple construction thereof, the travelling system thereof is large in size because a large loading ring is located which has a certain inclination corresponding to the lead angle at the outlet side of the drum, and because the capstan motor must also maintain the same inclination as above-mentioned. As a result, it is difficult to provide a compact and a light-weight of the product.
The new "U" loading type recorder which has been proposed to overcome the above-mentioned drawback is constructed to take up the tape at the inlet side of the rotary drum. The outlet side of the rotary drum is disposed in parallel with the base plane of the deck. By this construction, the diameter of the loading ring can be reduced. The loading ring and the capstan motor are horizontally disposed. As a result, there is an advantage of greatly reducing the total size of the travelling system as compared with that of the old "U" loading type recorder. In this new "U" loading type recorder, however, at least three fixed and inclined posts are disposed at the inlet side of the rotary drum. Consequently, the travelling load of tape is increased, as compared with that of the old "U" loading type recorder. This becomes an obstacle to a smooth and stable travel of the tape. In order to overcome such problem, there is a need to provide a separate device for reducing the load acting on the rotating parts of the travelling system and for providing a stable travelling of the tape. However, the provision of such device makes the construction of travelling system complicated, thereby causing the cost of manufacture to be increased.
In the "M" loading type recorder, tape loading is effected by a pair of inclined posts horizontally guided to the inlet side and outlet side of the rotary drum. Accordingly, there are advantages of providing a compact travelling system and of simplifying the construction, as compared with those of the above-mentioned type recorders. In this type of recorder, however, the travel of tape is guided by a pair of inclined posts having a relatively large inclination, thereby causing the take up angle of tape to be enlarged. Thereby, the "M" loading type recorder is more undesirable than the above-mentioned other type recorders, when a travelling load is considered. The use of a separate impedance roller for overcoming the above-mentioned drawback also causes the construction of travelling system to be complicated and thereby the cost of manufacture to be increased. Moreover, each inclined post is a moveable post which is not fixed to the inlet or outlet side of the drum. Accordingly, each inclined post has to be fixedly and accurately held at a predetermined position thereof. However, an accurate positioning of the assembly of inclined posts is relatively difficult. This becomes an obstacle to a stable travel of the tape.